Juncus

Juncus is a genus of flowering plants in the rush family Juncaceae. It comprises about 300 species of herbaceous perennials and occasional annuals that typically grow in wetlands and damp habitats. Members have slender, cylindrical stems with leaves reduced to sheaths; rhizomes or creeping bases are common. The inflorescence is usually a dense cluster of small flowers, often at the stem tip. Flowers have six tepals and usually several stamens, and they are commonly wind-pollinated. The fruit is a small capsule containing many tiny seeds.

Distribution and habitat: Juncus is widespread in temperate and boreal regions and extends into subtropical zones. Species occupy wetlands, fens, meadows, salt marshes, riverbanks, and bogs, from alpine to coastal areas, with some forms adapted to cold or saline conditions.

Ecology and uses: Rushes stabilize soil and contribute to water filtration in wetlands. They provide habitat for invertebrates and are common in naturalistic plantings and water gardens. Some species are used in constructed wetlands for wastewater treatment and for erosion control and habitat restoration.

Taxonomy and notable species: Juncus is the largest genus in Juncaceae, closely related to Luzula. Notable species include Juncus effusus (soft rush), widespread in damp habitats, and Juncus balticus (Baltic rush), occurring in coastal and saline environments.

Conservation and cultivation: Many Juncus species are not threatened, but habitat loss threatens some wetlands. In cultivation, they prefer moist to wet soils and are used in ponds, bog gardens, and rain gardens. Propagation is by seed or division.